lightmode.js: Made theme preference save to localStorage

src/light-mode.js

@@ -1,5 +1,24 @@
-function themeToggle() {
+(function () {
     var element = document.body;
+    var theme = localStorage.getItem("colorscheme");
+    if (theme === null) {
+        localStorage.setItem("colorscheme", "dark")
+    }
+    if (theme === "light") {
+        element.classList.toggle("light-mode")
+    }
+})();
+
+function themeToggle() {
+    var theme = localStorage.getItem("colorscheme");
+    var element = document.body;
+    if (theme === "dark") {
         element.classList.toggle("light-mode");
+        localStorage.setItem("colorscheme", "light")
+    }
+    else {
+        element.classList.toggle("light-mode")
+        localStorage.setItem("colorscheme", "dark")
+    }
 
 }